CN212693089U - Semiconductor device and silicon photomultiplier - Google Patents
Semiconductor device and silicon photomultiplier Download PDFInfo
- Publication number
- CN212693089U CN212693089U CN202021741009.5U CN202021741009U CN212693089U CN 212693089 U CN212693089 U CN 212693089U CN 202021741009 U CN202021741009 U CN 202021741009U CN 212693089 U CN212693089 U CN 212693089U
- Authority
- CN
- China
- Prior art keywords
- single photon
- photon avalanche
- avalanche diode
- spad
- capacitor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 48
- 239000010703 silicon Substances 0.000 title claims abstract description 48
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 47
- 239000004065 semiconductor Substances 0.000 title claims abstract description 41
- 239000003990 capacitor Substances 0.000 claims abstract description 68
- 238000010791 quenching Methods 0.000 claims description 57
- 230000000171 quenching effect Effects 0.000 claims description 36
- 230000004044 response Effects 0.000 claims description 11
- 238000003384 imaging method Methods 0.000 abstract description 24
- 230000015556 catabolic process Effects 0.000 abstract description 20
- 230000035945 sensitivity Effects 0.000 abstract description 7
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 238000001514 detection method Methods 0.000 description 15
- 238000010586 diagram Methods 0.000 description 14
- 230000000875 corresponding effect Effects 0.000 description 9
- 238000012545 processing Methods 0.000 description 7
- 230000008878 coupling Effects 0.000 description 6
- 238000010168 coupling process Methods 0.000 description 6
- 238000005859 coupling reaction Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 230000003287 optical effect Effects 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 230000006870 function Effects 0.000 description 4
- 230000001960 triggered effect Effects 0.000 description 4
- 230000001413 cellular effect Effects 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000001465 metallisation Methods 0.000 description 2
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 2
- 229920005591 polysilicon Polymers 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 238000003491 array Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 230000000116 mitigating effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000005070 sampling Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/14609—Pixel-elements with integrated switching, control, storage or amplification elements
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/88—Lidar systems specially adapted for specific applications
- G01S17/89—Lidar systems specially adapted for specific applications for mapping or imaging
- G01S17/894—3D imaging with simultaneous measurement of time-of-flight at a 2D array of receiver pixels, e.g. time-of-flight cameras or flash lidar
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
- G01T1/16—Measuring radiation intensity
- G01T1/24—Measuring radiation intensity with semiconductor detectors
- G01T1/248—Silicon photomultipliers [SiPM], e.g. an avalanche photodiode [APD] array on a common Si substrate
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/02—Details
- H01L31/02016—Circuit arrangements of general character for the devices
- H01L31/02019—Circuit arrangements of general character for the devices for devices characterised by at least one potential jump barrier or surface barrier
- H01L31/02027—Circuit arrangements of general character for the devices for devices characterised by at least one potential jump barrier or surface barrier for devices working in avalanche mode
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
- H01L31/10—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors characterised by at least one potential-jump barrier or surface barrier, e.g. phototransistors
- H01L31/101—Devices sensitive to infrared, visible or ultraviolet radiation
- H01L31/102—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier or surface barrier
- H01L31/107—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier or surface barrier the potential barrier working in avalanche mode, e.g. avalanche photodiode
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S17/00—Systems using the reflection or reradiation of electromagnetic waves other than radio waves, e.g. lidar systems
- G01S17/88—Lidar systems specially adapted for specific applications
- G01S17/93—Lidar systems specially adapted for specific applications for anti-collision purposes
- G01S17/931—Lidar systems specially adapted for specific applications for anti-collision purposes of land vehicles
Abstract
The utility model discloses a semiconductor device and silicon photomultiplier. The semiconductor device is embodied as an imaging device, which may comprise a Single Photon Avalanche Diode (SPAD). Placing SPADs close together in an imaging device, such as a silicon photomultiplier, can have beneficial effects such as improved sensitivity. However, as SPADs become closer together, SPADs may become susceptible to crosstalk. Crosstalk is generally undesirable due to reduced dynamic range and reduced signal accuracy. To reduce crosstalk, capacitors or other components may be coupled between adjacent SPADs. When avalanche occurs over a given SPAD, the bias voltage can be lowered below the breakdown voltage. The capacitor may cause a corresponding voltage drop across the adjacent SPAD. The voltage drop across the adjacent SPAD reduces the over-bias of that SPAD, thereby reducing the sensitivity of the SPAD and thus reducing the chance of cross-talk.
Description
Technical Field
The present invention relates generally to semiconductor devices and silicon photomultipliers, and more particularly to imaging systems including Single Photon Avalanche Diodes (SPADs) with capacitive coupling for single photon detection.
Background
Modern electronic devices, such as cellular telephones, cameras, and computers, often use digital image sensors. An image sensor (sometimes referred to as an imager) may be formed from an array of two-dimensional image sensing pixels. Each pixel typically includes a photosensitive element, such as a photodiode, that receives incident photons (incident light) and converts the photons to an electrical signal. Each pixel may also include a microlens that overlaps and focuses light onto the photosensitive element.
Conventional image sensors may be affected by limited functionality in a number of ways. For example, some conventional image sensors may not be able to determine the distance from the image sensor to the object being imaged. Conventional image sensors may also have less than desirable image quality and resolution.
To increase sensitivity to incident light, Single Photon Avalanche Diodes (SPADs) are sometimes used in imaging systems. Single photon avalanche diodes may enable single photon detection. However, single photon avalanche diodes may be susceptible to optical crosstalk.
It is in this context that the embodiments described herein are presented.
SUMMERY OF THE UTILITY MODEL
The present invention is directed to a semiconductor device with capacitively coupled Single Photon Avalanche Diode (SPAD) for single photon detection with reduced optical crosstalk.
According to a first aspect, there is provided a semiconductor device comprising: a first single photon avalanche diode; a first quenching circuit coupled to the first single photon avalanche diode; a second single photon avalanche diode; a second quenching circuit coupled to the second single photon avalanche diode; and a capacitor coupled between the first single photon avalanche diode and the second single photon avalanche diode.
According to a second aspect, there is provided a silicon photomultiplier comprising: a first microcell including a first single photon avalanche diode and a first quenching circuit; a second microcell including a second single photon avalanche diode and a second quenching circuit; and at least one component coupled between the first and second microcells, the at least one component causing a voltage drop at the second single photon avalanche diode in response to an avalanche occurring in the first single photon avalanche diode to mitigate cross talk between the first and second microcells.
According to a third aspect, there is provided a semiconductor device comprising: a first single photon avalanche diode; a second single photon avalanche diode; and first and second overlapping conductive layers formed between the first and second single photon avalanche diodes, wherein the first and second overlapping conductive layers form a parallel plate capacitor between the first and second single photon avalanche diodes.
According to the utility model discloses a semiconductor device that is used for single photon detection's single photon avalanche diode with capacitive coupling it has the optical crosstalk that reduces.
Drawings
Figure 1 is a circuit diagram illustrating an exemplary single photon avalanche diode pixel, according to one embodiment.
FIG. 2 is a diagram of an exemplary silicon photomultiplier according to one embodiment.
FIG. 3 is a schematic diagram of an exemplary silicon photomultiplier with a fast output terminal according to one embodiment.
FIG. 4 is a diagram of an exemplary silicon photomultiplier including an array of microcells.
Fig. 5 is a schematic diagram of an exemplary imaging system including a SPAD-based semiconductor device, according to one embodiment.
FIG. 6 is a graph illustrating the relationship of an over-bias voltage to photon detection efficiency according to one embodiment.
FIG. 7 is a graph illustrating the relationship of an over-bias voltage to the probability of crosstalk according to one embodiment.
Figure 8 is a diagram illustrating an exemplary silicon photomultiplier with a single photon avalanche diode coupled together with a capacitor to reduce crosstalk, according to one embodiment.
FIG. 9 is a timing diagram of bias voltages of two microcells of FIG. 8, illustrating how the arrangement of FIG. 8 may be used to reduce crosstalk, according to one embodiment.
Figure 10 is a top view of an illustrative silicon photomultiplier showing how a parallel plate capacitance can be formed between adjacent single photon avalanche diodes according to one embodiment.
FIG. 11 is a diagram illustrating an exemplary silicon photomultiplier having a microcell coupled to two adjacent microcells to reduce crosstalk, according to one embodiment.
FIG. 12 is a diagram illustrating an exemplary silicon photomultiplier having a microcell coupled to four adjacent microcells to reduce crosstalk, according to one embodiment.
Detailed Description
Embodiments of the present invention relate to imaging systems including Single Photon Avalanche Diodes (SPADs).
Some imaging systems include an image sensor that senses light by converting impinging photons into electrons or holes (collected) that accumulate in pixel photodiodes within a sensor array. After the accumulation period is completed, the collected charge is converted into a voltage, which is provided to the output terminal of the sensor. In Complementary Metal Oxide Semiconductor (CMOS) image sensors, the charge-to-voltage conversion is done directly in the pixels themselves, and the analog pixel voltages are transferred to the output terminals through various pixel addressing and scanning schemes. The analog pixel voltages can also be subsequently converted on-chip to digital equivalents and processed in various ways in the digital domain.
On the other hand, in Single Photon Avalanche Diode (SPAD) devices, such as those described in connection with fig. 1-4, the photon detection principle is different. The photo-sensing diode is biased above its breakdown point and when an incident photon generates an electron or hole, that carrier initiates avalanche breakdown through the additional carrier being generated. The avalanche multiplication can produce a current signal that can be easily detected by a readout circuit associated with the SPAD. The avalanche process can be stopped (or quenched) by lowering the diode bias below its breakdown point. Thus, each SPAD may include passive and/or active quenching circuitry for stopping avalanche.
This concept can be used in two ways. First, only arriving photons may be counted (e.g., in low light applications). Second, SPAD pixels can be used to measure photon time-of-flight (ToF) from a synchronized light source to a scene object point and back to the sensor, which can be used to obtain a three-dimensional image of the scene.
Fig. 1 is a circuit diagram of an exemplary SPAD device 202. As shown in fig. 1, the SPAD device 202 includes a SPAD204 coupled in series with a quench circuit 206 between a first supply voltage terminal 210 (e.g., a ground supply voltage terminal) and a second supply voltage terminal 208 (e.g., a positive supply voltage terminal). In particular, the SPAD device 202 includes a SPAD204 having an anode terminal connected to the supply voltage terminal 210 and a cathode terminal directly connected to the quench circuit 206. SPAD devices 202 that include SPADs 204 connected in series with a quench resistor 206 are sometimes collectively referred to as optically triggered cells or "microcells". During operation of the SPAD device 202, the supply voltage terminals 208 and 210 may be used to bias the SPAD204 to a voltage above the breakdown voltage (e.g., apply the bias voltage Vbias to the terminal 208). The breakdown voltage is the maximum reverse voltage that can be applied to the SPAD204 that does not result in an exponential increase in leakage current in the diode. When the SPAD204 is reverse biased above the breakdown voltage in this manner, the absorption of a single photon can trigger a short but relatively large avalanche current by impact ionization.
The quench circuit 206 (sometimes referred to as a quench element 206) may be used to reduce the bias voltage of the SPAD204 to a level below the breakdown voltage. Lowering the bias voltage of the SPAD204 below the breakdown voltage stops the avalanche process and the corresponding avalanche current. There are a variety of ways to form the quench circuit 206. Quench circuit 206 can be a passive quench circuit or an active quench circuit. Once avalanche starts, the passive quenching circuit automatically quenches the avalanche current without external control or monitoring. For example, fig. 1 shows an example in which the quenching circuit 206 is formed using a resistor member. This is an example of a passive quench circuit.
This example of a passive quench circuit is merely exemplary. Active quenching circuits may also be used in the SPAD device 202. The active quench circuit may reduce the time it takes for the SPAD device 202 to reset. This may allow the SPAD device 202 to detect incident light at a faster rate than when using passive quenching circuitry, thereby improving the dynamic range of the SPAD device. The active quenching circuit can adjust the SPAD quenching resistance. For example, the quench resistance is set to a higher value before a photon is detected, and then minimized to reduce the recovery time once a photon is detected and avalanche quenched.
The SPAD device 202 can also include a readout circuit 212. There are a variety of ways to form the readout circuitry 212 to obtain information from the SPAD device 202. The readout circuit 212 may include a pulse counting circuit that counts arriving photons. Alternatively or in addition, readout circuitry 212 may include time-of-flight circuitry for measuring photon time-of-flight (ToF). Photon time-of-flight information can be used to perform depth sensing. In one example, the photons may be counted by an analog counter to form a light intensity signal as the corresponding pixel voltage. The ToF signal can also be obtained by converting the photon time of flight to a voltage. The example of an analog pulse counting circuit included in readout circuit 212 is merely exemplary. The readout circuitry 212 may include digital pulse counting circuitry, if desired. The readout circuitry 212 may also include amplification circuitry, if desired.
The example of read circuit 212 coupled to the node between diode 204 and quench circuit 206 in fig. 1 is merely exemplary. The sense circuit 212 may be coupled to the terminal 208 or any desired portion of the SPAD device. In some cases, quench circuit 206 can be considered integral with readout circuit 212.
Because the SPAD device can detect a single incident photon, the SPAD device can effectively image a scene with low light levels. Each SPAD may detect the number of photons received over a given time period (e.g., using a readout circuit that includes a counting circuit). However, as described above, each time a photon is received and an avalanche current is initiated, the SPAD device must be quenched and reset before it is ready to detect another photon. As the incident light level increases, the reset time becomes limited to the dynamic range of the SPAD device (e.g., the SPAD device is triggered on reset as soon as the incident light level exceeds a given level).
Multiple SPAD devices can be grouped together to help increase dynamic range. Fig. 2 is a circuit diagram of an exemplary group 220 of SPAD devices 202. The group or array of SPAD devices may sometimes be referred to as silicon photomultipliers (sipms). As shown in fig. 2, the silicon photomultiplier 220 may include a plurality of SPAD devices coupled in parallel between the first supply voltage terminal 208 and the second supply voltage terminal 210. Fig. 2 shows N SPAD devices 202 (e.g., SPAD device 202-1, SPAD device 202-2, SPAD device 202-3, SPAD device 202-4, SPAD device 202-N) coupled in parallel. More than two SPAD devices, more than ten SPAD devices, more than a hundred SPAD devices, more than a thousand SPAD devices, etc. may be included in a given silicon photomultiplier 220.
Each SPAD device 202 may sometimes be referred to herein as a SPAD pixel 202. Although not explicitly shown in fig. 2, the readout circuit for the silicon photomultiplier 220 may measure the combined output current from all SPAD pixels in the silicon photomultiplier. Configured in this manner, the dynamic range of an imaging system including SPAD pixels can be increased. Each SPAD pixel is not guaranteed to have a triggered avalanche current when an incident photon is received. SPAD pixels can have an associated probability of triggering an avalanche current upon receipt of an incident photon. There is a first probability that an electron is generated when a photon reaches the diode, followed by a second probability that the electron triggers an avalanche current. The total probability of a photon triggering an avalanche current can be referred to as the Photon Detection Efficiency (PDE) of the SPAD. Thus, grouping a plurality of SPAD pixels together in a silicon photomultiplier allows for more accurate measurement of incoming incident light. For example, if a single SPAD pixel has a PDE of 50% and receives one photon within a certain time period, the probability of not detecting a photon is 50%. With the silicon photomultiplier 220 of fig. 2, two of the four SPAD pixels will likely detect photons, thereby improving the image data for the provided time period.
The example of fig. 2 is merely exemplary, where multiple SPAD pixels 202 share a common output in a silicon photomultiplier 220. With an imaging system that includes a silicon photomultiplier with a common output for all SPAD pixels, the imaging system may not have any resolution in imaging the scene (e.g., the silicon photomultiplier may detect photon flux at only a single point). It may be advantageous to obtain image data over the array using SPAD pixels to allow higher resolution reproduction of the imaged scene. In cases such as these, SPAD pixels in a single imaging system may have a pixel-by-pixel readout capability. Alternatively, an array of silicon photomultipliers (each comprising more than one SPAD pixel) may be included in the imaging system. The output from each pixel or from each silicon photomultiplier may be used to generate image data of the imaged scene. The array may be capable of independent detection in an array of lines (e.g., an array having a single row, multiple columns, or a single column, multiple rows) or an array having more than ten, more than one hundred, or more than one thousand rows and/or columns (whether a single SPAD pixel or a plurality of SPAD pixels are used in a silicon photomultiplier).
As described above, although SPAD pixels have multiple possible use cases, the underlying techniques for detecting incident light are the same. All of the above examples of devices using SPAD pixels are collectively referred to as SPAD-based semiconductor devices. A silicon photomultiplier that includes a plurality of SPAD pixels having a common output may be referred to as a SPAD-based semiconductor device. SPAD pixel arrays with pixel-by-pixel readout capability may be referred to as SPAD-based semiconductor devices. A silicon photomultiplier array with a silicon-by-silicon photomultiplier readout capability may be referred to as a SPAD-based semiconductor device.
Figure 3 shows a silicon photomultiplier 30. As shown in fig. 3, the SiPM 30 has a third terminal 35 capacitively coupled to each cathode terminal 31 to provide fast readout of the avalanche signal from the SPAD 33. When the SPAD 33 emits a current pulse, a portion of the voltage variation generated at the cathode 31 will be coupled into the third ("fast") output terminal 35 via the mutual capacitance. Using the third terminal 35 for readout avoids impaired transient performance due to the relatively large RC time constant associated with the bias circuit biasing the top terminal of the quench resistor.
Those skilled in the art will appreciate that a silicon photomultiplier includes a primary bus 44 and a secondary bus 45 as shown in fig. 4. Secondary bus 45 may be directly connected to each individual microcell 25. The secondary bus 45 is then coupled to the primary bus 44, which is connected to the bond pads associated with terminals 37 and 35. Typically, secondary bus 45 extends vertically between columns of microcells 25, while primary bus 44 extends horizontally adjacent outer rows of microcells 25.
Fig. 5 shows an imaging system 10 with a SPAD-based semiconductor device. The imaging system 10 may be an electronic device such as a digital camera, computer, cellular telephone, medical device, or other electronic device. The imaging system 10 may be an imaging system on a vehicle (sometimes referred to as an onboard imaging system). The imaging system may be used for LIDAR applications.
The imaging system 14 may include one or more SPAD-based semiconductor devices 14 (sometimes referred to as semiconductor devices 14, SPAD-based image sensors 14, or image sensors 14). One or more lenses 28 may optionally cover each semiconductor device 14. During operation, the lens 28 (sometimes referred to as an optic 28) may focus light onto the SPAD-based semiconductor device 14. The SPAD-based semiconductor device 14 may include SPAD pixels that convert light into digital data. SPAD-based semiconductor devices can have any number of SPAD pixels (e.g., hundreds, thousands, millions, or more). In some SPAD-based semiconductor devices, each SPAD pixel may be covered by a respective color filter element and/or microlens.
The SPAD-based semiconductor device 14 may optionally include additional circuits such as logic gates, digital counters, time-to-digital converters, bias circuits (e.g., source follower load circuits), sample and hold circuits, Correlated Double Sampling (CDS) circuits, amplifier circuits, analog-to-digital (ADC) converter circuits, data output circuits, memory (e.g., buffer circuits), address circuits, and the like.
Image data from the SPAD-based semiconductor device 14 may be provided to the image processing circuitry 16. The image processing circuitry 16 may be used to perform image processing functions such as auto-focus functions, depth sensing, data formatting, adjusting white balance and exposure, enabling video image stabilization, face detection, and so forth. For example, during an autofocus operation, the image processing circuitry 16 may process data acquired by the SPAD pixels to determine the magnitude and direction of lens movement (e.g., movement of the lens 28) required to focus an object of interest. The image processing circuitry 16 may process the data acquired by the SPAD pixels to determine a depth map of the scene.
The imaging system 10 may provide a number of advanced functions for the user. For example, in a computer or advanced mobile phone, the user may be provided with the ability to run user applications. To accomplish these functions, the imaging system may include input-output devices 22, such as a keypad, buttons, input-output ports, a joystick, and a display. Additional storage and processing circuitry, such as volatile and non-volatile memory (e.g., random access memory, flash memory, hard disk drives, solid state drives, etc.), microprocessors, microcontrollers, digital signal processors, application specific integrated circuits, and/or other processing circuitry may also be included in the imaging system.
The input-output devices 22 may include output devices that operate in conjunction with SPAD-based semiconductor devices. For example, a light emitting component may be included in the imaging system to emit light (e.g., infrared or any other desired type of light). The semiconductor device 14 may measure the reflection of light off of an object to measure the distance to the object in a LIDAR (light detection and ranging) scheme.
Generally, it may be desirable for silicon photomultipliers (sipms) to have SPADs that are closely arranged together. The close spacing of the SPADs can increase the photosensitive area of the silicon photomultiplier with a corresponding improvement in sensitivity. However, as SPADs become closer together, SPADs may become susceptible to crosstalk.
Crosstalk occurs when a photon incident on a first microcell causes an avalanche current on both the first microcell and an adjacent microcell. The avalanche current of a first microcell can in turn generate a photon that travels to an adjacent second microcell during optical crosstalk and causes an avalanche current in the second microcell. This type of optical crosstalk is generally undesirable due to reduced dynamic range and reduced signal accuracy.
One way to reduce crosstalk is to reduce the amount of over-biasing of the single photon avalanche diode. The over-bias voltage may refer to an amount by which the bias voltage exceeds the breakdown voltage of the SPAD. The breakdown voltage is the maximum reverse voltage that can be applied to the SPAD that does not result in an exponential increase in leakage current in the diode. The more the bias voltage exceeds the breakdown voltage (e.g., the greater the over-bias voltage or amount of over-bias), the more sensitive the SPAD becomes.
Fig. 6 is a graph showing how photon detection efficiency increases with increasing over-bias. The total probability of a photon triggering an avalanche current can be referred to as the Photon Detection Efficiency (PDE) of the SPAD. In general, SPAD is desired to have a higher PDE because this improves the sensitivity and performance of sipms. Increasing the amount of over-biasing can result in an increase in PDE. The linear profile of fig. 6 is merely exemplary and is intended to illustrate the general relationship between the over-bias and the PDE.
While increasing the over-bias has the beneficial effect of increasing the photon detection efficiency, increasing the over-bias may also undesirably increase the crosstalk. Fig. 7 is a graph showing how the crosstalk probability increases with increasing over-bias. Increasing the amount of over-biasing can result in an increased probability of crosstalk (e.g., the probability of an avalanche on a first microcell causing an avalanche on a neighboring microcell). The linear profile of fig. 7 is merely exemplary and is intended to illustrate the general relationship between the over-bias and the crosstalk probability. Thus, as shown in the graphs of fig. 6 and 7, increasing the over-bias may advantageously increase PDE, but undesirably increase cross-talk. To reduce the crosstalk probability of SPAD-based semiconductor devices, there may be capacitive coupling between adjacent microcells. Due to capacitive coupling, avalanche current on a first microcell may cause a decrease in bias voltage on an adjacent microcell. Therefore, the chance of occurrence of crosstalk can be reduced in the adjacent microcell.
FIG. 8 is a schematic diagram of an exemplary silicon photomultiplier with a capacitor between adjacent microcells in the silicon photomultiplier. FIG. 8 shows four exemplary SPAD devices 202-1, 202-2, 202-3, and 202-4 (sometimes referred to as microcells 202-1, 202-2, 202-3, and 202-4). The SPAD devices have a similar structure as shown in fig. 1 and 2, with each SPAD device having a single photon avalanche diode and a quench resistor coupled between a first supply voltage terminal 210 (e.g., a ground supply voltage terminal) and a second supply voltage terminal 208 (e.g., a positive supply voltage terminal).
To reduce crosstalk, capacitors may be coupled between adjacent SPADs within a silicon photomultiplier. As shown in FIG. 8, capacitor 232-1 is coupled between node A of SPAD 202-1 (e.g., the cathode of SPAD 202-1) and node B of SPAD202-2 (e.g., the cathode of SPAD 202-2). Capacitor 232-2 is coupled between the cathode of SPAD 202-3 and the cathode of SPAD 202-4.
The capacitive coupling between the SPAD 202-1 and the SPAD202-2 can help reduce cross talk between the SPAD 202-1 and the SPAD 202-2. Consider an example of a photon that causes an avalanche current in the SPAD 202-1. Due to the quenching of the avalanche current, node a will have a corresponding drop below the breakdown voltage. Due to the presence of capacitor 232-1, node B may have an associated proportional voltage drop at node B. This reduces the over-bias voltage of the SPAD202-2, thereby temporarily suppressing the PDE of the SPAD 202-2. This reduces the chance of crosstalk causing an avalanche in the SPAD 202-2.
Herein, a microcell having an avalanche caused by an incident photon may sometimes be referred to as a trigger microcell, an attack microcell, or the like. A microcell that is susceptible to crosstalk from a triggering microcell that is adjacent to the triggering microcell may be referred to as an interfered microcell, an adjacent microcell, or the like. Each capacitor between SPADs in a silicon photomultiplier may have any desired capacitance. Generally, a larger capacitance can increase the magnitude of the voltage drop at the disturbed microcell caused by the avalanche at the triggering microcell. The capacitance of each capacitor may be greater than 2 femto farads (fF), greater than 4 femto farads, greater than 6 femto farads, greater than 8 femto farads, greater than 10 femto farads, greater than 12 femto farads, less than 2 femto farads, less than 4 femto farads, less than 6 femto farads, less than 8 femto farads, less than 10 femto farads, less than 12 femto farads, between 2 femto farads and 12 femto farads, between 6 femto farads and 15 femto farads, between 4 femto farads and 10 femto farads, and so on.
Fig. 9 is a timing diagram illustrating exemplary voltages at nodes a and B in fig. 8 to illustrate how capacitor 232-1 suppresses crosstalk. As shown, at time t1The voltage at both node A and node B may be V1。V1May be an over-bias voltage of 5V or some other desired over-bias voltage. Because both voltages are over-biased, the SPAD can have a relatively high photon detection efficiency.
At t2Here, microcell 202-2 may have an avalanche caused by an incident photon on microcell 202-2. When an avalanche occurs, the quenching circuit of microcell 202-2 may be used to reduce the bias voltage of microcell 202-2 to a level below the breakdown voltage. Lowering the bias voltage of microcell 202-2 below the breakdown voltage stops the avalanche process and the corresponding avalanche current. The timing diagram shows how the node B voltage drops sharply in response to avalanche current and subsequent quenching caused by incident photons. For example, the node B voltage may be reduced below the breakdown voltageVoltage V of voltage3。
Meanwhile, due to capacitive coupling between node a and node B, the voltage drop at node B may cause a corresponding voltage drop at node a. As shown in FIG. 9, the voltage at node A may also be at t2And drops. The node a voltage does not drop as much as the node B voltage. For example, the voltage at node A drops to a voltage V that is still above the breakdown voltage2. However, the over-bias voltage is still from V1Decreases to V2. This drop in the voltage of node a will reduce the photon detection efficiency of microcell 202-1. When the over-bias is reduced in this manner, the microcell 202-1 is less likely to trigger an avalanche. Therefore, avalanche caused by crosstalk will be less likely to occur (due to temporary sensitivity degradation corresponding to avalanche in neighboring microcells).
After quenching the avalanche, the voltages at both node a and node B may increase back to the initial over-bias level. At t3The opposite situation is shown where microcell 202-1 has an avalanche triggered by an incident photon. This results in the voltage drop at node A reaching a voltage V below the breakdown voltage3. Node B has reached V2Resulting in a decrease in sensitivity during the time period in which microcell 202-2 is susceptible to crosstalk from avalanche microcell 202-1. After quenching, the voltage is again restored to V1At the initial over-bias level.
FIG. 10 shows one illustrative example of forming a capacitor between microcells 202-1 and 202-2. As shown in fig. 10, microcell 202-1 may have a corresponding single photon avalanche diode 204-1 and microcell 202-2 may have a corresponding single photon avalanche diode 204-2. The SPAD204-1 can be electrically connected to the conductive layer 244 using contacts 246. The SPAD 204-2 can be electrically connected to the conductive layer 242 using contacts 246. Conductive layers 242 and 244 may be planar overlapping conductive layers. One or more dielectric layers may be formed between the conductive layers. Thus, a parallel plate capacitance (capacitor 232-1) is formed between conductive layers 242 and 244. Conductive layers 242 and 244 may sometimes be referred to as capacitor plates 242 and 244. The conductive layers can have any desired dimensions and can be plane-parallel (e.g., conductive layer 242 is formed in a first plane and conductive layer 244 is formed in a second plane parallel to the first plane).
The conductive layer 242 can be coupled to the cathode of the SPAD 204-2 and the conductive layer 244 can be coupled to the cathode of the SPAD 204-1. Fig. 10 shows an arrangement of this type, similar to the arrangement in fig. 8. However, this example is merely exemplary. In another possible arrangement, the conductive layers 242 and 244 can be electrically connected to the anode of the SPAD. One or more vias can be used to make electrical connections between the SPAD and the conductive layer. The conductive layers 242 and 244 can have other electrically separate portions on different sides of the SPAD204-1 and SPAD 204-2, if desired. Other portions of the conductive layers 242 and 244 may be used to transmit signals within the silicon photomultiplier, provide shielding for the silicon photomultiplier, and the like.
The arrangement of fig. 10 is merely exemplary. Any desired conductive layer or component can be used to form capacitor 232-1 between microcells 202-1 and 202-2. For example, in one alternative arrangement, conductive layers 242 and 244 can be coplanar, and a capacitance (e.g., capacitor 232-1) can be formed by a fringing field between the two conductive layers. Conductive layers 242 and 244 may be formed of metal or other desired materials. In some cases, a resistive layer such as polysilicon may be used to form one or both plates in the capacitor. For example, layer 244 in fig. 10 may be formed of polysilicon and layer 242 in fig. 10 may be formed of metal (or vice versa).
Examples in which each microcell is capacitively coupled to an adjacent microcell have been shown and discussed in fig. 8-10. This example is merely exemplary. It should be understood that a microcell may be capacitively coupled to more than one adjacent microcell, as shown in fig. 11 and 12.
In fig. 11, each microcell is coupled to two adjacent microcells. As shown, a capacitor 232-1 is formed between microcells 202-1 and 202-2. Similarly, a capacitor 232-2 is formed between microcells 202-2 and 202-3. With this arrangement, microcell 202-2 can mitigate crosstalk when a photon triggers an avalanche in microcell 202-1 or microcell 202-3. Thus, crosstalk mitigation in silicon photomultipliers is improved. This pattern may be repeated over the silicon photomultiplier 220. For example, capacitor 232-3 is formed between microcells 202-4 and 202-5, and capacitor 232-4 is formed between microcells 202-5 and 202-6.
In yet another example, a silicon photomultiplier may have a microcell capacitively coupled to four additional microcells, as shown in fig. 12. Microcell 202-5 is coupled to microcell 202-2 through capacitor 232-1, to microcell 202-4 through capacitor 232-2, to microcell 202-8 through capacitor 232-3, and to microcell 202-6 through capacitor 232-4. This pattern can be repeated over a silicon photomultiplier if desired.
These arrangements are merely exemplary. In general, any desired number of microcells in any desired pattern can be capacitively coupled to reduce crosstalk. For example, a set of 2 x 2 microcells may be capacitively coupled to reduce crosstalk, or a set of 3 x 3 microcells may be capacitively coupled to reduce crosstalk. Capacitors can be formed between microcells in the same row and adjacent column (e.g., horizontally adjacent), between microcells in the same column and adjacent row (e.g., vertically adjacent), or between microcells in adjacent row and adjacent column (e.g., diagonally adjacent). Each pair of coupled microcells may be coupled through a plurality of metallization layers. Multiple microcells may be coupled together using multiple metallization layers, if desired.
Additionally, the example of a single capacitor coupled between the microcells to mitigate cross talk is merely exemplary. When a voltage drop occurs across a triggering microcell, the capacitor causes a small but proportional voltage drop across the adjacent microcell. Additional components or combinations of components may be used in place of the capacitor to achieve this effect. For example, a resistor or other component (rather than a capacitor) may be coupled between adjacent microcells.
According to one embodiment, a semiconductor device may include: a first single photon avalanche diode; a first quenching circuit coupled to the first single photon avalanche diode; a second single photon avalanche diode; a second quenching circuit coupled to the second single photon avalanche diode; and a capacitor coupled between the first single photon avalanche diode and the second single photon avalanche diode.
According to another embodiment, the capacitor may be coupled to a first cathode of the first single photon avalanche diode and a second cathode of the second single photon avalanche diode.
According to another embodiment, the capacitor may be coupled to a first node interposed between the first single photon avalanche diode and the first quenching circuit, and the capacitor may be coupled to a second node interposed between the second single photon avalanche diode and the second quenching circuit.
According to another embodiment, the first single photon avalanche diode and the first quenching circuit can be coupled in series between a first bias voltage supply terminal and a second bias voltage supply terminal.
According to another embodiment, the second single photon avalanche diode and the second quenching circuit may be coupled in series between the first bias voltage supply terminal and the second bias voltage supply terminal.
According to another embodiment, the capacitor may be a first capacitor, and the semiconductor device may further include: a third single photon avalanche diode; a third quenching circuit coupled to the third single photon avalanche diode; and a second capacitor coupled between the first single photon avalanche diode and the third single photon avalanche diode.
According to another embodiment, the semiconductor device may further include: a fourth single photon avalanche diode; a fourth quenching circuit coupled to the fourth single photon avalanche diode; a fifth single photon avalanche diode; a fifth quenching circuit coupled to the fifth single photon avalanche diode; a third capacitor coupled between the first single photon avalanche diode and the fourth single photon avalanche diode; and a fourth capacitor coupled between the first single photon avalanche diode and the fifth single photon avalanche diode.
According to another embodiment, the capacitor may comprise a first overlapping plate and a second overlapping plate interposed between the first and second single photon avalanche diodes.
According to another embodiment, the first plate of the capacitor may be electrically connected to the first single photon avalanche diode and the second plate of the capacitor may be electrically connected to the second single photon avalanche diode.
According to another embodiment, the capacitor may be configured to cause a voltage drop at the second single photon avalanche diode in response to an avalanche occurring in the first single photon avalanche diode.
According to another embodiment, the first single photon avalanche diode may be configured to experience a first voltage drop in response to an avalanche occurring in the first single photon avalanche diode, and the capacitor may be configured to cause a second voltage drop at the second single photon avalanche diode in response to the first voltage drop to reduce crosstalk between the first single photon avalanche diode and the second single photon avalanche diode.
According to another embodiment, the second voltage drop may be less than the first voltage drop.
According to one embodiment, a silicon photomultiplier may include: a first microcell including a first single photon avalanche diode and a first quenching circuit; a second microcell including a second single photon avalanche diode and a second quenching circuit; and at least one component coupled between the first and second microcells, the at least one component causing a voltage drop at the second single photon avalanche diode in response to an avalanche occurring in the first single photon avalanche diode to mitigate cross talk between the first and second microcells.
According to another embodiment, the at least one component may comprise a capacitor.
According to another embodiment, the capacitor may have a first plate coupled to a selected one of a cathode and an anode of the first single photon avalanche diode, and the capacitor may have a second plate coupled to a selected one of a cathode and an anode of the second single photon avalanche diode.
According to another embodiment, the silicon photomultiplier may further include: a third microcell including a third single photon avalanche diode and a third quenching circuit; and at least one additional component coupled between the first and third microcells, the at least one additional component causing a voltage drop at the third single photon avalanche diode in response to an avalanche occurring in the first single photon avalanche diode to mitigate cross talk between the first and third microcells.
According to another embodiment, the at least one additional component may comprise an additional capacitor.
According to one embodiment, a semiconductor device may include: a first single photon avalanche diode; a second single photon avalanche diode; and first and second overlapping conductive layers formed between the first and second single photon avalanche diodes. The first and second overlapping conductive layers may form a parallel plate capacitor between the first and second single photon avalanche diodes.
According to another embodiment, the first electrically conductive layer may be electrically connected to the first single photon avalanche diode and the second electrically conductive layer may be electrically connected to the second single photon avalanche diode.
According to another embodiment, the parallel plate capacitor may cause a temporary reduction in the over-bias voltage on the second single photon avalanche diode when avalanche causes the voltage of the first single photon avalanche diode to drop below the breakdown voltage.
The foregoing is considered as illustrative only of the principles of the invention, and numerous modifications are possible to those skilled in the art. The above-described embodiments may be implemented individually or in any combination.
Claims (10)
1. A semiconductor device, comprising:
a first single photon avalanche diode;
a first quenching circuit coupled to the first single photon avalanche diode;
a second single photon avalanche diode;
a second quenching circuit coupled to the second single photon avalanche diode; and
a capacitor coupled between the first single photon avalanche diode and the second single photon avalanche diode.
2. The semiconductor device of claim 1, wherein the capacitor is coupled to a first cathode of the first single photon avalanche diode and a second cathode of the second single photon avalanche diode.
3. The semiconductor device of claim 1, wherein the capacitor is coupled to a first node interposed between the first single photon avalanche diode and the first quench circuit, and wherein the capacitor is coupled to a second node interposed between the second single photon avalanche diode and the second quench circuit.
4. The semiconductor device of claim 1, wherein the first single photon avalanche diode and the first quench circuit are coupled in series between a first bias voltage supply terminal and a second bias voltage supply terminal, and wherein the second single photon avalanche diode and the second quench circuit are coupled in series between the first bias voltage supply terminal and the second bias voltage supply terminal.
5. The semiconductor device of claim 1, wherein the capacitor is a first capacitor, the semiconductor device further comprising:
a third single photon avalanche diode;
a third quenching circuit coupled to the third single photon avalanche diode;
a second capacitor coupled between the first single photon avalanche diode and the third single photon avalanche diode;
a fourth single photon avalanche diode;
a fourth quenching circuit coupled to the fourth single photon avalanche diode;
a fifth single photon avalanche diode;
a fifth quenching circuit coupled to the fifth single photon avalanche diode;
a third capacitor coupled between the first single photon avalanche diode and the fourth single photon avalanche diode; and
a fourth capacitor coupled between the first single photon avalanche diode and the fifth single photon avalanche diode.
6. The semiconductor device of claim 1, wherein the capacitor comprises first and second overlapping plates interposed between the first and second single photon avalanche diodes, wherein the first plate of the capacitor is electrically connected to the first single photon avalanche diode, and wherein the second plate of the capacitor is electrically connected to the second single photon avalanche diode.
7. The semiconductor device of claim 1, wherein the first single photon avalanche diode is configured to experience a first voltage drop in response to an avalanche occurring in the first single photon avalanche diode, wherein the capacitor is configured to cause a second voltage drop at the second single photon avalanche diode in response to the first voltage drop to reduce crosstalk between the first single photon avalanche diode and the second single photon avalanche diode, and wherein the second voltage drop is less than the first voltage drop.
8. A silicon photomultiplier, comprising:
a first microcell including a first single photon avalanche diode and a first quenching circuit;
a second microcell including a second single photon avalanche diode and a second quenching circuit; and
at least one component coupled between the first and second microcells, the at least one component causing a voltage drop at the second single photon avalanche diode in response to an avalanche occurring in the first single photon avalanche diode to mitigate cross talk between the first and second microcells.
9. The silicon photomultiplier of claim 8, wherein the at least one component comprises a capacitor, the silicon photomultiplier further comprising:
a third microcell including a third single photon avalanche diode and a third quenching circuit; and
at least one additional component coupled between the first and third microcells, the at least one additional component causing a voltage drop at the third single photon avalanche diode in response to the avalanche occurring in the first single photon avalanche diode to mitigate cross talk between the first and third microcells, wherein the at least one additional component comprises an additional capacitor.
10. A semiconductor device, comprising:
a first single photon avalanche diode;
a second single photon avalanche diode; and
first and second overlapping conductive layers formed between the first and second single photon avalanche diodes, wherein the first and second overlapping conductive layers form a parallel plate capacitor between the first and second single photon avalanche diodes.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US201962891804P | 2019-08-26 | 2019-08-26 | |
| US62/891,804 | 2019-08-26 | ||
| US16/668,245 US11275186B2 (en) | 2019-08-26 | 2019-10-30 | Imaging devices with capacitively coupled single-photon avalanche diodes |
| US16/668,245 | 2019-10-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN212693089U true CN212693089U (en) | 2021-03-12 |
Family
ID=74679698
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202021741009.5U Active CN212693089U (en) | 2019-08-26 | 2020-08-19 | Semiconductor device and silicon photomultiplier |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US11275186B2 (en) |
| CN (1) | CN212693089U (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20220174188A1 (en) * | 2020-11-30 | 2022-06-02 | Microsoft Technology Licensing, Llc | Spad array for intensity image sensing on head-mounted displays |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8884240B1 (en) * | 2009-06-08 | 2014-11-11 | Radiation Monitoring Devices, Inc. | Position sensitive solid-state photomultipliers, systems and methods |
| GB201004922D0 (en) | 2010-03-24 | 2010-05-12 | Sensl Technologies Ltd | Silicon photomultiplier and readout method |
| US9634156B2 (en) * | 2012-05-25 | 2017-04-25 | Sensl Technologies Ltd. | Semiconductor photomultiplier and readout method |
| WO2014172697A1 (en) * | 2013-04-19 | 2014-10-23 | Lightspin Technologies, Inc. | Integrated avalanche photodiode arrays |
| US9768211B2 (en) * | 2015-05-06 | 2017-09-19 | LightSpin Technologies Inc. | Integrated avalanche photodiode arrays |
| JP6932580B2 (en) * | 2017-08-04 | 2021-09-08 | ソニーセミコンダクタソリューションズ株式会社 | Solid-state image sensor |
| US10451748B1 (en) * | 2018-12-05 | 2019-10-22 | Canon Medical Systems Corporation | Readout circuit for a silicon photomultiplier (SiPM) array using charge sharing and anger logic |
-
2019
- 2019-10-30 US US16/668,245 patent/US11275186B2/en active Active
-
2020
- 2020-08-19 CN CN202021741009.5U patent/CN212693089U/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| US20210063588A1 (en) | 2021-03-04 |
| US11275186B2 (en) | 2022-03-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11428826B2 (en) | Silicon photomultipliers with split microcells | |
| US11764314B2 (en) | Scattering structures for single-photon avalanche diodes | |
| US11943542B2 (en) | Imaging devices with single-photon avalanche diodes having sub-exposures for high dynamic range | |
| US11942498B2 (en) | Microlenses for semiconductor device with single-photon avalanche diode pixels | |
| US20240105753A1 (en) | Semiconductor devices with single-photon avalanche diodes and light spreading lenses | |
| US20230154959A1 (en) | Microlens structures for semiconductor device with single-photon avalanche diode pixels | |
| US20240105748A1 (en) | Semiconductor packages with an array of single-photon avalanche diodes split between multiple semiconductor dice | |
| CN212693089U (en) | Semiconductor device and silicon photomultiplier | |
| US20230253513A1 (en) | Semiconductor Devices with Single-Photon Avalanche Diodes and Light Scattering Structures | |
| CN211404506U (en) | Semiconductor device with a plurality of transistors | |
| US11646335B2 (en) | Semiconductor devices with single-photon avalanche diodes and rectangular microlenses | |
| US10784302B1 (en) | Semiconductor device with single-photon avalanche diode pixels and a light attenuating layer | |
| US20230387332A1 (en) | Scattering structures for single-photon avalanche diodes | |
| US20240055537A1 (en) | Semiconductor Devices with Single-Photon Avalanche Diodes, Light Scattering Structures, and Multiple Isolation Structures | |
| US20230215960A1 (en) | Semiconductor devices with single-photon avalanche diodes and hybrid isolation structures | |
| US20220158019A1 (en) | Semiconductor packages with single-photon avalanche diodes and prisms |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |